R.A. Dickey will make his final start of the season Friday night at the Rogers Centre and he hopes the powers that be keep the Rogers Centre roof closed.

“I don’t know if they will” Dickey said Thursday in Baltimore. “I hope they will so it’ll give us one more measurement before the year’s up.”

After his last home start — a 2-0 victory over the New York Yankees — Dickey said he looked forward to the end of the year when he had a good sample size of starts when the roof was both closed and open to glean “valuable feedback” for next year.

Heading into his final start of the season the knuckleballer’s dome splits are stark.In seven starts with the roof closed he’s 4-2 with a 3.76 ERA. In 10 starts with the dome open he’s 3-4 with a 5.73 ERA.

Even after a full season it’s still a small sample which includes plenty of non-roof-related variables namely the quality of the competition and the quality of Dickey’s knuckleball.